Description

BOR crank XM557 1X SmartSpindleSystem 1 times LK 76

The XM557 crank the German manufacturer BOR based on the proven XC666. However, changes and advancements let the weight of the XM557 continue tumbling down. In detail, this means a weight-reduced Lockring that secures the optimized Spider. The crank arms have been calculated once again and could lose a few grams. The arms are mounted on an aluminum shaft with 30 mm diameter to meet even most powerful sprinter with best Steigikeit. BOR typically comes also the proven Smart Spindle System is used, which makes it possible to build the crank in almost any context. Furthermore, even the Spider can replace. The crank is therefore prepared for any future changes.

The CNC machined chainrings BOR aluminum are as always hardened in a special process with a glass mount peening and then anodized with double the usual thickness. This Double Surface Treatment gives the leaves by a significantly increased shelf life! The chainrings have specific narrow-wide teeth that prevent the chain may come off. In conjunction with a Sram or Shimano Shadow Type2 + derailleur, which have greatly increased bias of the cage, the chain is reliably held in place without chain guide.